Proximity Service ProSe means a solution for supporting communication between devices physically located to be proximate to each other. In more detail, ProSe is intended to discover an application which is operated in proximate devices and finally support an exchange operation of application-related data.
For example, it may be considered that ProSe is applied to applications such as social network service (SNS), business, and games.
ProSe may be referred to as device-to-device (D2D) communication. In other words, ProSe means a communication scheme that a direct link is configured between a plurality of devices (for example, user equipments (UEs) to allow the devices to directly transmit and receive user data (for example, voice, multimedia data, etc.) to and from each other without through a network. ProSe communication may include user equipment-to-user equipment (UE-to-UE) communication, peer-to-peer communication, etc. Also, the ProSe communication scheme may be applied to machine-to-machine (M2M) communication, machine type communication (MTC), etc. Accordingly, ProSe is considered as a solution for solving load of a base station, which is caused by data traffic which is rapidly increased. Also, with the introduction of ProSe, advantages of process reduction of the base station, power consumption reduction of devices which join in ProSe, increase of data transmission rate, increase of network capacity, load distribution, cell coverage enlargement, etc. will be expected.